Cellular phenolic resin materials



CELLULAR PHENOLIC RESIN MATERIALS Frank W. Thomas, Burbank, and Eli Simon, Los Angeles,

Calif., assignors to Lockheed Aircraft Corporation, Burbank,

No Drawing. Application June 14, 1951, i Serial No. 231,673

4 claims. (Cl. 260-25 This invention relates to foamed or cellular plastics and relates more particularly to porous or cellular phenolic resin plastic materials or products.

Prior to our invention, cellular phenolic resin plastics were proposed and introduced. However, "so far as we are aware, the acceptance of these materials has been quite limited owing to their poor or weak physical strength characteristics. The low-strength nature of these prior materials has been] such that they are not well adapted to structural applications where they are' required to serve as load carriers. Furthermore, although the'prior pheno lic foams may be suitable in some situations as thermal and/or acoustical insulation, and the cell size may not be uniform, there often being regions of overly large cells, resulting in a non-uniform insulating effect.

It is an object of our invention to provide low-density cellular or foamed phenolic resin plastics that are suitable both for insulating and structural applications. If desired, low-weight tenuous foams of relatively low strength may be produced for the type of uses or applicationswhere space-filling, thermal and/or acoustical insulation is required as in walls, ceilings, panels, etc. the material being of substantial uniform texture-and cell size throughout, or the foams or materials of theinvention may be compounded to be suitable for structural uses wherein they serve as structural. load iassuming. sections 'or. components as in laminated sandwich type panels, internally filled and reinforced elements, or both as insulating andload assuming materials as in refrigerator insulation, building panels,'etc. I p

Another object of the invention is to provide porous or cellular plastic materials of this character in which the sizes of the gasfilled cells may be varied or controlled to obtain the optimum I characteristics and performance for the particular or intended applications. For example, where thezmaterial is to beused as insulation, it maybe-cornpounded to havetyery small-cells whereas when intended for structural applications the formulation may be such' as to, result in cells of larger diameter.

Another object of the invention is toprovide cellular,

phenolic resin materials that have excellent adherence to the surfaces of practically all solids when allowed to react in situ, that is when poured in place or otherwise applied as a liquid reactant mass and allowed to react in its intended final location. This characteristic or ability of themat'erial wellsuits it for many applications where insulating and/ or structural light-weight filler material is best utilized by being poured in place or applied as a liquid or partially liquid mass to react and finally and uniformly adhere to the internal surfaces of the parts.

. A further object of the invention is to provide phenolic resin foamed or cellular materials of this nature which are the products of mutual or dual reaction; i. e. (1) an initial reaction between a special acid catalyst and a gassing agent such as aluminum, and (2) a second reaction taking place during the first and increasing the chain. length of the diphenol alcohols of the resol type phenolic resins g is uncontrolled and the product is oftentimes non-uniform.

Furthermore, the controlled reaction" provides ample 'p'ouring, spreading or working timeffacilitatingthe-handling to yield a fluid resol, the viscosity of the latter beingcone;

employed, the chain growing at a slow and controlled rate as a result of the 'acid combination or blend constituting the catalyst, one acid serving to reduce or slowdown the rate of reaction of the other. The character of the gassing medium employed, preferably a metal leafingpowder, and

' the nature of the blend of acids forming the catalyst, ma-

terially contribute to the controlled and regular foaming reaction of the phenolic resin mass resulting inaproduct having uniform cell structure and distinguishing'from the prior products of this general kind wherein the reaction or use of the materials.

Other objectives and features will become apparent to those skilled in the art from the following detailed description of the invention. In preparing the cellular or foamed plastic materials, we employ a phenolic resin or resol,a 'gassingQ agent or medium, and a special catalyst. 4

, The resin or resins are primarily'derived from'the i'eaction of phenols and aldehydes and their various analogues. v The extent of the reaction is determined bythe', specific gravity, viscosity and water miscibility of the resin or resol and is governed partially, at least, 'by thetype of catalyst employed. The phenolic resinswhichwe utilize Patented May: 8, 1956.

in the formulationsof the 11u1agpmau s of the invcn-,-, tion may be'defined as acid catalyzable water, miscible;

resol type resins which are the reaction products ofphenO- saturated or unsaturated alkyls or aryl substituted phenols};

with aldehydes, such as formaldehyde, alkyl aldehydes aryl aldehydes, poly aldehydes, furan aldehydes, amino or halo aldehydes, nitro substituted aldehydes. 'Anyj'c'opl-l' bination of these with alkyl or aryl 'amines,',a ldoses, alctihols or epoxy compounds may be used when further modification is required. It has been foundthat the physical strength properties of 1 the resultant cellular or; foamed products can be controlled to'some extent by vai'y-' ing or adjusting the specific gravity of the phenolic 'resin'f employed. Thus a substantial range of physical as'weli as chemical properties may be obtained in the resultant foamed material where the specific gravity of the phenolic resin employed is variedbetween 1.15 and 1.35,;: :It,lia's also been found that a rather close or accurate adjust-. ment or standardization of the specific gravity for'a'n'y' given set of physical properties of the resultant product is desirable.

The reaction of a given phenol with a,

specific aldehyde takes place in accordance with-theres- The resinification 5 ate, metallic hydroxide or metallic salthaving. an alkaline hydrolysis such as. sodium citrate, sodium oxalatefetc trolled by the extent of the reaction and the amouii t'of water removed.

y In preparing a typical phenolic resin for, usein ,ouii making our cellular materialsa mixture containingz is reacted at the reflux temperature from'l5 minutes to The mass is then neutralized with a suitable 2 hours.

acid such as acetic, phosphoric, oxalic,'or the like,.to a 7 pH of about 7 and is vacuum distilled to remove the, excess water until the specific gravity ranges between 1.15.;

a and 1.35. The synthesis of certain of the phenolic resins, as employed in the invention, require catalysts, generally basic type compounds such as metallic oxides, carbonates, and hydroxides. Barium hydroxide may be found to be preferred catalyst. Other suitable catalysts are:

. RESIN 1 Phenol l'mol. Eormaldehyde... r. 1 to 2.5 mols. Barium hydroxideSHnO 0.003 to 0.020 mol.

I RESIN 2 Pm-isopropyl phenol 1 mol. Formaldehyde.-- 1 to 2.5 mols. Calcium carbonat 0.003 to 0.020 moi.

I RESIN a diphenol being in the proportion oi {1 mol total (the RPsec butylidenefrom 5 to 75% by mol weight).

Formaldehyde l to 2.5 mols. Calcium oxide 0.003 to 0.020 mol.

RESIN 4 1 mol total (the'0,0diphenol being in PhenoL- the proportion of from 5 .to 757 by mol weight). a Formaldehyde. 1 to 2.5'mols.

Potgssium oxalate 0.003 to 0.020 mol.

. I RES'IN5 6 1 mol total (the parachloro phenol being in the proportion of from 5 to m Pheml" 75%by mo'l Weight). Formaldehyde- 1 .to 2.5 mols. Barium hydroxide 8H:0.. 0.003 to 0.020 mol.

7 y RESIN I mol total (the parahydroxy benzoic ggg g bemom Bold acid being in the proportion of from 4 to 75% by mol weight). Formaldehyde i to 2.5 mols.

Barium hydroxide SHzO 0.003 to 0.020 mol.

" RESIN 7' Phenol 1 mol total (the cresol being in the Cresol '(ortho, meta, para or proportion of from 5 to 75% by mol mixture-thereof) weight Formaldehyde 1 to 2.5 mols. Calcium hydroxide 0.003 to 0.020 mol.

RESIN 8 Phenol 1 ttl(th r z lbin in Formaldehyde 3 mos 9 a e l proportion of from 5 to 507 by Fmfuml mol weight). a Barium hydroxide SHxO 0.003 to 0.020 mol.

. RESIN 9 Phenol being in the proportion of from 5 'to 50% by mol weight). Bariumchydroxideiiiflio .0. 003 to 0.020 mol.

1 mol. {1 to 2.5 mols total (the aeetaldehyde RESIN 10 Phenol 1 mol.

l to 2.5 mols total (the benzaldehyde being in the proportion of from 5 to Formaldehyde 50% by mol weight). Barium hydroxide SE20 0.003 to 0.020 mol.

RESIN 11 Phenol 1 molfiotal (the para nitro phenol being Para (ortho) nitro phenol" 3J gggi gf of from 5 175% by Formaldehyde l to 2.5 mols. Barium hydroxide SH O 0.003 to 0.020 mol.

' RESIN 12 1 mol total (the naphthol being in the fig fif beta) naphtha prripg gion of from 5 to by mol we g Formaldehyde 1 to 2.5 mols. Magnesium carbonate 0.003 to 0.020 mol.

RESIN 13 Phen 1 mol. Methyl ethyl ketone- 0.5 to 1 mol Formaldehyde 1 to 2.5 mols. Barium hydroxideBHaO 0.003 to 0.020 mol.

RE SIN 14 0.003 to 0.020 mol.

RESIN 15 Phenol "ii z 's lttl(th l lbin m Glyoxal (as polyglyoxal)- mo S 0 a e g yoxa e g proportion oi-irom 5 to 507 mol Formaldehyde weight) Barium hydroxide SHzO 0.003 to 0.020 mol.

RESIN 16 Phenol 1 mol. Ortho hydroxybenzyl alchol. 0.5 to 1 mol. Formaldehyde 1 to.2.5 mols. Barium hydroxide 81110 0.003 to 0.020 mol.

RESIN 17 Phenol 1 mol. Furtur 1 to 2.5 mols. Ketone acetone, methyl ethyl 0.5 to 1 mol.

ketone Barium hydroxide-SE 0 0.003 to 0.020 mol.

RESIN 18 Phenol 1 mol. Formaldehyde.-- 1 to 2.5 mols. Polyvinyl alcohol l to 15% by Weight .of the total weight of the phenol and formaldehyde.

Barium hydroxide 8Hz0 0.003 to'0.020 mol.

We have found that the use of polyvinyl alcohol .and/ or polyvinyl alcohol chloride in preparing the phenolic resins or resols for incorporation in the foamed or cellular plastics of the invention is productive of superior results. The polyvinyl alcohol or chloride is used in the proportion range of from 0.5 to 20% by weight of the combined weight of the other components. The polyvinyl alcohol serves to control the exothermic temperature during the foaming reaction allowing greater freedom of action and handling of the reactant mixture during the foaming period. The polyvinyl alcohol acts as a viscosity modifier and increases the toughness, elasticity and flexibility of the final products.

It will be noted that resins 18 to 28 include polyvinyl alcohol in their formulations.

RESIN 19 Phenol 1 mol. Terpineol .25 to 1 mol. Formaldehyde l to 2.5 mols. Barium hydroxide EH40. 0.003 to 0.020mol. Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

RESIN 20 Sodium benzene sulfonate. 0.5 to 1 mol. Phenol 1 mol.

Polyvinyl alcohol i to 15% by weight of the combined Weightoi the other components.

RESIN 21 Glycerol 0.25 120.1 moi. Phenol 1 mol. Formaldehyde 1 to 2.5 mols. Barium hydroxide 0.003 to 0.020 mol. Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

In preparing Resin 21, other polyhydric alcohols, such as glycols and amino alcohols may be used instead of .the glycerol in the same proportion as the glycerol.

RESIN22 Phenol 1 mol. Formaldehyde 1 to 2.5 mols. Barium hydroxide 8H2O 0.003 to 0.020 mol. Epichlorohydrin to 20% by weight oi the combined rlveiight of the phenol and-formaldey e. Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

RESIN 23 1 1 mol.

1 to 2.5 mols total (thafurlural being in the proportion of from 5 to 50% by mol weight).

Polyvinyl alcohol 5 to ,50 grams. Barium hydroxide SE20 0.003 to 0.020 mol.

, RESIN 24 Phenol 1 mol total (the bisphenol'beingin the Bisphenol A (P,Ppropylideneproportion of from 5 to 75% by mol (diphenol). weight I if 1 r Formaldehyde 1 to 2.5 mols.

Epichlorohydrin... 0.25 to 1 mol. arium hydroxide. 0.003 to 0.020 mol;

Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

RESIN 2s I v 1 mol total (the P,Pdiphenol being in the proportion of from 5 to 75% by mol weight). 0.25 to 1 mol. l to 2.5 mols. I Barium hydroxide 0.003 to 0.020 mol. Polyvinyl alcohol 1 to 15% by weight oi the combined weight of the other components. RESIN 2s Phenol 1 mol total (the resorcinol being in the ResorcmoL" grgggrgion oi from 5 to 75% mol Formaldehyde l to 2.5 mols. Barium hydroxide SH O 0.003 to 0.020 mol. Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

nnsmzv 1 mol total (the catechol being in the Phenol Catechol 0, m, p) g i flg by Formaldehyde 1 to 2.5 mols. Barium hydroin'de 81120.. 0.003 to 0.020 mol. Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

. RESIN28 Phenol" 1 mol. Formaldehyd 1 to 2.5 mols -n-Propylamine- 0.25 to 1 mol.

Barium hydroxide 81120 0.003 to 0.020 mol. 1 Polyvinyl alcohol 1 to 15% by weight of the combined weight of the other components.

Where formaldehyde is employed in synthesizing any of the above phenolic resols, it may preferablybe used in an aqueous solution having a formaldehyde concentration of from 30 to 40% by weight, usually about 37% by weight.

The catalysts used inthe reactant cellular materialproducing mixture are important in obtaining the desired products of good physical characteristics. The particular catalyst employed, together with the gassing agent or agents provide the flexibility, controlled rise of the phenolic mass, and the adhesion,.final cure and excellent physical strength of the resultant cellular "plastie TThe aciducatalyst servesto liberate or generate hydrogen, nitrogen, carbondioxide, or other gas tofproduce'the foaming of the resin mass andalso eifects a cure of the foamed resin. We prefer to employ a mixture or blend of acids and water as the catayst and have found that such a blend is particularly eflective in foaming the phenolic resins and in producing a cellular plastic product of "superior physical characteristics. A concentration range v.of the catalyst'blend or mixtureof from /2 to 20% by weight of the, resin has been found to be satisfactory. -One catalyst which we have found to be particularly effective comprises a benzene sulfonic acid,or the equivalent, and a phosphoric acid. The phosphoricacid serves to limit or control the cure rate of the foamed resin mass. The sulfonic acids or sufonic acid derivatives that we may use'in this catalyst blend include benzene sulfonic acid,

phenol sulfonic acid, meta benzene, disulfonic acid, and

toluene sulfonic acid. Such a catalyst, which'we shall term Catalyst I, may include, forexample:

' The benzene sulfonic acid, or any of the equivalents thereof named above, the phosphoric acid solution, and the water of Catalyst I may beemployed in the proportion ranges of:

Catalyst I a b c d c Benzene sulfonic acid (or Percent Percent Percent Percent Percent equivalent) 20 20 20 5 50 85% aqueous orthophosphoric acid 10 45 70 75 25 Water 70 35 10 20 25 subsequcnt'exarnples the catalyst will be designated Catalyst I- a, Catalyst I-b; Catalyst I-c, etc., reference If desired, phosphorous pentbeing to the above table. oxidemaybe substituted for the orthophosphoric acid in Catalysts I-a to I-e inclusive.

The invention includes, in some instances, the use of unsaturated polyester-phenolic resin blends in formulating the cellular or foamed plastics. In such cases unsaturated polyester resins are mixed or blended with a phenolic resin, such as pr'eviously described, to form the resin blend or mixture that is catalyzed or foamed by the additives. Examples of unsaturated polyesterv resins -'that may be employedin this manner may be formulated Diethylene glycol.

' from:

RESIN 29 Diethylene glycol Fumaric acid--.

sebacic acid 1 mol.-

Acid N 0. between 35 and 60 and preferably about 45.

RESIN 30 Ethylene glycol. Maleic anhydride Acid No. between 20 and 60 and preferably about 40.

' RESIN 31 Maleic anhydride.

Acid No. between Where the resin blend or mass includes such unsaturated polyester resins, we prefer to use a catalyst including a boron complex such as boron trifluoride. The following is an example 'of such a, catalyst, which will BF3 ether complex 1 The following are illustrative of the boron complexes that may be employed in formulating Catalyst IL' Boron trifluoride phenol complex Boron trifluoride ethyl ether complex Boron trifluoride butyl ether complex Boron trifluoride ammonia complex The ingredients of Catalyst II may have the same ranges .of-proportions as those of Catalyst I set forth in the above table, with the boron trifluoride complexvconstituting between 1 and 5% by weight of the total.

1- Thegassing agent, or agents, that maybe employed in :preparinglhe: cellulanphenolic vproducts .may-be selected .wfrom,.carbonates,..bicarbonates; or tnitrites.of ..potassium,

sodium, magnesium, zinc andaluminnm. .I..Such-,agents, when catalyzed by or reacted with the selected catalyst, liberate a gas or gasses to'form the cells of the foamed ;:or.cellulanplastic. However, superior results are obtained Jill/hell. a-selectcdmetallieleafingpowdersor. arcombinati'on of metallicz-leafingipowders is..usediras the'gassinguagent. We wish. to..emphasize that th'e'se outstandingly: superior :results. are achievedby. the useofleafing powdenfasrldistinguished from.-non-.leafing-..powder. ..Theleafingpowder, by reasonofthe. tphysicaltshapeibf titsmparticles ..or ..leaflets,? readilydistributes... uniformly...t-hroughout j. the mass of resin as distinguished from non-leafing .powder where the particles do not have the ability to distribute in this manner but,.on the contrary, tend to settle or gather in lumps or masses. Furthermore, in the manufacture of metallic leafing powder its particles or platelets are lubricated by and coated with a :lubricant. is believed .to cause an effective. distribution of the metal :particles in the phenolic resin or phenolic and unsaturated polyester resin blend, while at the same timedelaying or controlling the access of the acid. catalyst .to. the. metal particles. It is believed that these. mechanisms. onactions ;may account inpartfor.the.unexp.ectedly .uniform cell -size. and uniform cell distribution).throughthe....mass./ of foamingresin, the well distributed metal particlesandthe controlled reaction with themetalproducing theuinusual results. The metallic leafin'g; powder, or combination of .-.metallic.-.-leafing powders, .may be. used inthe .range'from .01% to by weight of thetotalformulato produce a. cellular product where the. density.ranges...from pounds per cubic footto 1 pound, -or .less, per. cubic .foot. .Where'the above mentioned carbonates or. Ibicarbonates are used as. gassing agents, they maybe employed innthe ..proportion-offrom .0l% to.20%-tby-weight-ofzithe total weight of. the formulation. The:metallicleafing"powder,

which we employ in our formulations, is either aluminum leafing powder, magnesium leafing powder, iron leafing powder, or zinc leafing powder. We have obtained outstanding results using aluminum leafing powder vofsnot less than-100 mesh and'preferablyapproximately-400 mesh.

In the following formulations for the cellular phenolic plastics incorporatingthe metallic leafing powders and in the subsequent examples the proportions are irnpercentages by Weight of the total weight. Examples 1', 2 and 3 are illustrative of various concentrations of the metallic leafing powder gassing agent.

EXAMPLE 1 Percent Resin No. 1 "90.0 Aluminum leafing powder,.400 mesh 0.1

Catalyst I-b (containing 20% benzene-sulfonic acid and orthophosphoric acid aqueous solution) Where. the .gassing. agent is..used in tthisflrelatively'small proportion 'thereis a'low rise of theresinmass -andthe resultant cellularproduct has a=relative=high*density.

.EXAMELE 2 crPercent Resin No. 8 590.0 Aluminum leafing powder, .400 mesh 0.4

Catalyst I-a, containing20%. benzene sulfonicttacid and 10% of the.:orthophosphoric"acid.aqueous solution v 9.6

The: concentration -of 'Jgassing agent or aluminum leafing powder of Example 2 provides -for theproduction; oficel- :lular 'foams orproducts of medium-density.

This coating EXAlHPLE 3 I ."Percent 'R'esinNoI l -3900 Aluminumdeafing powder, 400" mesh ""20.0

Catalyst I-b, containing 20%= benzene sulfonic acid and 45% of the orthophosphoricacid-aqueous solution 1.8.0

T'lihis-concentrationuof. the metallic leafing powder results in alight. tenuous cellular-or foamed product.

Referringeagaintox the above describedCatalyst II, this type of catalyst is primarily intended for use with a phenolic resin blend containingan unsaturated polyester resin which is tfhe reaction: product of unsaturated acids...or *alco'h'olswith cach other or withsaturatedor mnsaturated polybasic acids andfior-piolyhydric alcoholsm-Morespecifically these unsaturated polyester'or alkydre'sins are'the reaction products between a, B-unsaturated organic acids chosen? from the; group including :r-naleic, fumaric, itaconic, chlormaleic andrcitraoonic acids and tpolyhydric alcohols, preferably those containingonlyxprimaryi-hydroxyl groups for rapid esterification, sucheaslthqglycols, ande whichwnjay: contain. as modifying substances- 'dibasic acids that do not contain groups that will react by polymerization with ethylenic-containing groups, i. e.

such as phthalic-.-.anhydr ide,.--adipic acid, .succinic...acid, sebacic acid, etc. The. unsaturated 'polyester resins may be employed in the proportion of from 20% to 88% of the total weight of the resins. Examples 4 and 4-A are ltypicalq formulations employing an. unsaturated polyester resin such as above described.

- EXAMPLE 4 1 Percent Unsaturated polyester Resin No. 29 46.0 Phenolic Resin No. 1 45.0 lCat-alystr No.1'II 8.7 Aluminum leafing powderg-400 mesh 0.3

- EXAMPLE 4A Percent Unsaturated polyester ResinNo. 30 66.0 Phenolic Resin No. 1 31.0 Catalyst No. II r 8.7 Aluminum leafing powder, 400mesh f. 0.3

The' following Examples 5 to' 7 inclusive, are representative .of the formulations incorporating phenolic .resins produced .from' or inclir'dingphenol, .catechol, quinol; pyrog'allol', resorcin'ol a and 3, naphthol'g'and' 'anthrol.

3 Examples- 8,-9 and '10,- which 'foll'owyirrcorporate 'phenoneresins made fromsubstituted'phenols*representd by such "phenols as- -ortho-,' meta-paranitrophenol;*ortho-= or paradinitr ophenoly ortho-,- paraaminophenol;--ortho-- or *paradiaminophenol; -ortho-, parachlorobenzene; ran'd "ortho-g-'paradichlorobenzene.

following Examples, 11, 12,. and 13, are representativeof-the employment ,ofa classxof phenolic resins wherein an-aldehyde other than formaldehyde is employed in. preparingtheresin. Various aldehydes may be used with any of the phenols previously considered and examples of such aldehydesare acetaldehyde, crotonaldehyde, polyformaldehyde, benzaldehyde', furfural, heptaldehyde,-'gloyoxal, or substituted aldehydes;

' "EXAMPLE '1'1' Percent Resin NO. 23 ..,.a. a Catalyst 'I-b p y a 1.0 Aluminum leafing powder, 400 mesh EXAMPLE 12 Percent Resin No. 17 94.9 Catalyst I-a 5.0 Iron leafing powder 0.1

EXAMPLE 13 Percent Resin No. 90.0 Catalyst I-a 5.0 Magnesium leafing powder 5.0

Examples 14 and 15 which follow, exemplify the employment of phenolic resins containing ketones employed in effecting modification of the phenolic resin such as acetone, methyl ethyl ketone, and benzophenone.

EXAMPLE 14 Percent Resin No. 13 98.7 Catalyst I-b 1.0 Aluminum leafing powder, 422 mesh 0.3

EXAMPLE 15 Percent Resin No. 17 90.0 Catalyst I-b 5.0 Aluminum leafing powder, 422 mesh 5 .0

Examples 16 and 17 which follow, are representative of formulations employing phenolic foams made from phenolic resins modified by reacting phenols such as phenol, catechol, quinol, pyrogallol, resorcinol, naphthol and substituted phenols such as ortho-, meta-para-nitrophenol; orthoor paradinitrophenol; o1tho-, para amino-phenol; etc. with amines such as alkyl amines: propylamine, amylamine, secpropylamine; and aryl amines: aniline, xylidine, and toluene.

. 10 The following Examples 18, 1 9 and'20, include phenolic resins requiring the" reaction of phenols and substituted phenols such as phenol, catechoLquinol, resorcinol,,.0rtho,-,

ineta-para-nitrophenol, forthoor paradinitrophenol, ortho-, para amino'phenol, or the like, with aldehydes such as polyformaldehyde, acetaldehyde, crotonaldehyde, fur- 'fural, etc. and with various compounds having active hydroxyl terminal groupingssuch as glyceroL; mannitol and terpineol. v l

. AM E a Inpreparing the foamed or cellularphenolic resin mater-ials 'of' the invention the selected phenolic resin or resol, or the selected blend of phenolic resol and unsaturated 'polyesterresin and the gassing agent, for example the leafiiig powdenare thoroughly mixed together to form one component or package. Other additives such as dyes, fillers, etc. when used are also mixed with these ingredients. In a like manner the ingredients of Catalyst I or II are mixed together to form another component or pack age. When it is desired to prepare and apply or use the foamed product these two packages are mixed together and the resultant reactant mixture is then applied by pouring, brushing, blading, dripping, or the like. The foaming reaction which produces the cellular resin product is accompanied by exothermic heat which sets the foam or cellular mass and it is desirable to post cure the product for several hours at slightly elevated temperatures.

It should be understood that the invention is not based upon or dependent upon the theories which we have expressed. Nor is the invention to be regarded as limited to the express procedure or materials set forth, these details being given only by way of illustration and to aid in clarifying the invention. We do not regard such specific details as essentialto the invention except insofar as they are expressed by way of limitation in the following claims in which it is our intention to claim all novelty inherent in the invention as broadly as is permissable in view of the prior art.

We claim:

1. The method of making a cellular plastic material which comprises the incorporation in an acid catalyzable, water miscible phenol-aldehyde resol having a specific gravity of between 1.15 and 1.35 and a pH of about 7 of from about 0.01% to about 20% of the total weight of the other ingredients of a gassing agent selected from the class consisting of: aluminum leafing powder, magnesium leafing powder, iron leafing powder, zinc leafing powder, and then mixing with said resol-gassing agent mixture a catalyst in the amount of from about 0.5% to 20% of the weight of the resol, the catalyst containing from about 5% to 50% benzene sulfonic acid, from about 10% to 75% of an concentration of orthophosphoric acid in an aqueous solution, the catalyst reacting with the resolgassing agent mixture to consume the gassing agent and form the cellular material.

2. The method of making a cellular plastic material which comprises the incorporation in an acid catalyzable, water miscible phenol-aldehyde resol having a specific gravity of between 1.15 and 1.35 and a pH of about 7 of from about 0.01% to about 20% of the total weight of the. other ingredientsmf a, gassingggent selectedxfrom t the-1 class consisting .of Taluminunflefingpowdenimagpowder afidfihen mixing Withs'did resol.-gassing vagent "mixture a. catalyst in'the amount ofirom about. 015% to 201%"6f the weight of'theresOl/the catalyst being-an aqueous acidicblend of benzene siilfoniciacidafld o'rtho'phos- Iphoricac'id'which consume and gass'ifies the gassing agent '10 form" the cellular material.

3. The method ofw ,making-cellular plastic material -.which-. -comprises the incorporation in an acid catalyzable, Mater miscible phenol-aldehyde resol having aa specific i-gravityof' between 1.15 and 1.35 and a pI-Lof about7 iof from 0.01% m' 2 0%. ofi--.the. ,tot'a1.weight;1.ofathe .other ingredients of a gassing agent selected from'the group consisting of: aluminum le iifin'g powder, magnesium leafing -powder, iron leafing powder, zinc leafing powder,. and then mixingwitirsaid resolgassingagenrmixture a catalyst containing about--20 %"benzenesulfonie acid; about45i% of an 'SWr-eoneentra'tion "bf 'oi'tho'phos'phoric "ac'id' 'in' an aqueous solution and Iabout* 3S -:water to react with the iresolvgassing agent mixture to consume the gassing agent sand form a .ce1lu1a1:.phenolic. material, thewatalyst b'eing remployedinlheproportion.v0f0.5%-10 20 of-the weight of the resol.

'4. The method which comprisemmikingmnanapproximate percentage by weightlbasis'. 9(1%=ofuanacidcatalyzrable' water miscible "phenolaldehyde..resolshivingt a; pH of about? and a specifiggraizity of between Llliand 1*."35 prepar'ed'from 1' .niollphenol; frorri 1.1a limolsformalde- 112 hyde and from 0.00? to"-i0.-020.=nnols barium hydroxide from 10% to 25% of an"85% concentration-.-faozthophosphoric acid in an aqueous solution and from 10% to 70% water, to react withthe resin=leafing powder mixture to'jgas'sify the aluminum powder and form amellular 'phenolicmterial;"the catalyst'being'nsedim'1he; pzop'ortion to"constitme thrbalance ofthe'"mix.

References Citedrinwheifile of this patent UNITED STATES PATENTS 2,3 3 7,874 'DAlelio -I'Dee? 283119.43 123761653 'Boyer ...i-.. 'May,22', ;1946 "23981703 "Gardner 'Apr.

3. 254465429 Nielsonwt '1 al. 2';559,'891 Meyer -',57J;28O *f Siri'toM'etfial. -e :2;582 228 i -B-rihkema "Han. 15, 1932 92,629,698 Ste'rling Feb."* 24, @9 53 TFOREIGN' PATENTS 361,910 GreatwBritain .."1'Nov;::16,rfl31 481,069 Great Britainm- Mar. 4, 1938 OTHER REFERENCES GermanPlastics-Prauzticeby-l3e "Bell; -Gloo1fafidffihg'3in, l 946rpages455rand*464. 

2. THE METHOD OF MAKING A CELLULAR PLASTIC MATERIAL WHICH COMPRISES THE INCORPORATION IN AN ACID CATALYZABLE, WATER MISCIBLE PHENOL-ALDEHYDE RESOL HAVING A SPECIFIC GRAVITY OF BETWEEN 1.15 AND 1.35 AND A PH OF ABOUT 7 OF FROM ABOUT 0.01% TO ABOUT 20% OF THE TOTAL WEIGHT OF THE OTHER INGREDIENTS OF A GASSING AGENT SELECTED FROM THE CLASS CONSISTING OF: ALUMINUM LEAFING POWDER, MAGNESIUM LEAFING POWDER, IRON LEAFING POWDER, ZINC LEAFING POWDER, AND THEN MIXING WITH SAID RESOL-GASSING AGENT MIXTURE A CATALYST IN THE AMOUNT OF FROM ABOUT 0.5% TO 20% OF THE WEIGHT OF THE RESOL, THE CATALYST BEING AN AQUEOUS ACIDIC BLEND OF BENZENE SULFONIC ACID AND ORTHOPHOSPHORIC ACID WHICH CONSUME AND GASSIFIES THE GASSING AGENT TO FORM THE CELLULAR MATERIAL. 